Month: September 2016

If you’re doing anything web related, chances are you’ve heard about Bootstrap. If by now you still don’t know what Bootstrap is, or you just want to find a bootstrap tutorial for beginners to get a better overview of what it is and what it does best, you’ve come to the right place.

Bootstrap is a powerful toolkit – a collection of HTML, CSS, and JavaScript tools for creating and building web pages and web applications. It is a free and open source project, hosted on GitHub, and originally created by (and for) Twitter.

After its open source release in 2011, Bootstrap became popular very quickly, and not without reason. Web designers and web developers like Bootstrap because it is flexible and easy to work with. Its main advantages are that it is responsive by design, it maintains wide browser compatibility, it offers consistent design by using re-usable components, and it is very easy to use and quick to learn. It offers rich extensibility using JavaScript, coming with built-in support for jQuery plugins and a programmatic JavaScript API. Bootstrap can be used with any IDE or editor, and any server side technology and language, from ASP.NET to PHP to Ruby on Rails.

With Bootstrap, web developers can concentrate on the development work, without worrying about design, and get a good looking website up and running quickly. Conversely, it gives web designers a solid foundation for creating interesting Bootstrap themes.

The source code version comes styles source code written in Less (or Sass), all the JavaScript, and accompanying documentation. This allows more ambitious designers and developers to change and customize, at their will, all the provided styles, and to build their own version of Bootstrap. But if you are not familiar with Less (or Sass), or you are just not interested in changing the source code, don’t worry. You can just use the precompiled vanilla CSS. All the styles can be overridden later by using custom styles.

File Structure

We’ll focus on the precompiled version, which can be downloaded here. When you download the zip archive and uncompress it, the basic file structure looks like this:

The Bootstrap structure is pretty simple and self-explanatory. It includes precompiled files that enable quick usage in any web project. Besides compiled and minified CSS and JS files, it also includes fonts fromGlyphicons, and the optional starting Bootstrap theme.

This structure can be easily incorporated in your own project’s file structure by just including the Bootstrap files exactly as they come out of the zip archive, or if it suits your project better, you can rearrange these files and place them anywhere you like. Just be sure that the Glyphicons fonts folder is on the same level as the CSS folder.

It is important to start any HTML with a HTML 5 Doctype declaration, so that browsers know what kind of a document they can expect. The head contains three important <meta> tags that must be declared first, and any additional head tags must be added after these. If you want to support older browsers like IE8, you can also include HTML 5 shim in the head, which will enable use of HTML5 elements in older browsers, andRespond.js, that will polyfill CSS3 Media Queries, in the old versions of Internet Explorer.

Although this is not very important if you are targeting only modern browsers.

JavaScript files are added to the end of the body to allow the web page to load visibly before any JavaScript is executed. jQuery is needed for Bootstrap plugins, and needs to load before bootstrap.js. If you aren’t using any of Bootstrap’s interactive features, you can also omit these files from the source.

This is the bare minimum that is needed to get a basic Bootstrap layout up and running. If you’re a developer, you’ll probably want to take a look at some more advanced examples at Bootstrap’s examples page. If you’re a designer, or just looking for inspiration, Bootstrap Expo showcases sites that are built using Bootstrap. As we’ll see later, every part of Bootstrap can be easily customized in CSS. But if that’s not your thing, and you are looking for a slightly different look and feel from the prepackaged Bootstrap themes, there are a lot of free, open source and premium themes available from sources like Bootswatch and WrapBootstrap.

Components

Bootstrap comes bundled with basic HTML and CSS design templates that include many common UI components. These include Typography, Tables, Forms, Buttons, Glyphicons, Dropdowns, Buttons and Input Groups, Navigation, Pagination, Labels and Badges, Alerts, Progress Bars, Modals, Tabs, Accordions, Carousels, and many others. Many of these use JavaScript extensions and jQuery plugins.

These templates are made available as well-factored CSS classes that you can apply to your HTML to achieve different effects. This makes using Bootstrap very convenient. By using semantic class names like .success, .warning and .info, these components are easily reusable and extensible. But while Bootstrap uses descriptive class names that have meaning, it isn’t specific about implementation details. All classes can be overridden with custom CSS style and color, and still the meaning of the class will stay the same.

Grids

Before we dive more into Bootstrap components and design templates, it is important to mention one of the major features that Bootstrap introduced in version 3: a mobile-first design philosophy, which resulted in a Bootstrap that is responsive by design. The end result is that Bootstrap easily and efficiently scales with a single code base, from phones, through tablets, to desktops.

This responsiveness is achieved using a fluid grid system that can be applied to appropriately scale up to 12 columns according to the size of the device or viewport. Grids provide structure to the layout, defining the horizontal and vertical guidelines for arranging content and enforcing margins. Grids also offer an intuitive structure for viewers, because it’s easy to follow a left to right, or a right to left flow of content moving down the page. Before grids, and before CSS was so powerful, grid based layouts were achieved by using tables, where the content would be arranged inside table cells. As CSS became more mature, a number of CSS frameworks for grid-based layouts started to appear. These include YUI grids, 960 GS and blueprint, to name a few.

To use the Bootstrap grid system, a few rules need to be followed. Grid column elements are placed inside row elements, which create horizontal groups of columns. You can have as many rows as you want on the page, but columns must be immediate children of rows. In a full row, the column widths will be any combination that adds up to 12, but it is not mandatory to use all 12 available columns.

Rows need to be placed either in a fixed-width layout wrapper, which has a .container class and a width of 1170px, or in full-width layout wrapper, which has a .container-fluid class, and which enables the responsive behavior in that row.

The Bootstrap grid system has four tiers of classes: xs for phones (<768px), sm for tablets (≥768px), md for desktops (≥992px), and lg for larger desktops (≥1200px). These basically define the sizes at which the columns will collapse or spread horizontally. The class tiers can be used in any combination to get dynamic and flexible layouts.

It is possible to disable page responsiveness completely. This will basically disable the “mobile site” aspects of Bootstrap. Just keep in mind that if you disable responsiveness, any fixed-width component, such as a fixed navbar, will not be visible when the viewport becomes narrower than the page content. For a non-responsive container, that means a width of 970px. Also in this case, navbars won’t collapse in mobile views as described later.

Typography

Beginning developers often assume their pure and un-styled HTML will look the same across all browsers. Unfortunately, every browser has its own default “user agent” style sheet that is applied to the HTML, and no two browsers have the same defaults. For example, heading font sizes are not consistent across browsers, some unordered and ordered lists have left margins and others have left padding, browsers apply custom borders and padding to the HTML body, and even buttons are rendered differently across browsers. To solve all these inconsistencies, different CSS “reset” rules were born that define consistent style defaults.

Bootstrap brings some more goodies to table besides pure CSS reset. It comes with normalize.css, an HTML5-ready alternative to CSS resets, and it also has some well-designed defaults of its own. For example, Bootstrap sets the global default font-size to 14px, with a line-height of 1.428. The default font is changed to Helvetica/Arial, with sans serif fallback. All these styles are applied to the <body> and all paragraphs, with the addition that <p> (paragraphs) receive a bottom margin of half their computed line-height (10px by default). Besides these defaults, there are also customizable styles for standard HTML tags that bring more consistency to the text, such as highlighted text (<mark>), deleted text (<del> and <s>), underlined text (<u>), small text (<small>), and bold text (<strong>). Alignment classes help to arrange content on the page more easily by using .text-left, .text-center, .text-right, .text-justify and .text-nowrap classes. There are also predefined styles for block quotes, and unordered and ordered list, with inline options, just to name a few. To get a full list, head to the Bootstrap Typography page.

One interesting thing that Bootstrap also makes possible is that you can use, for example, heading styles by using either the <h1> tag, or the .h1 class. The latter will match the styling of the <h1> heading, but will allow the text to be displayed inline.

Forms

Forms have come a long way over the years, and today using a web form is one of the most common activities performed while browsing the web. While HTML5 introduced a number of new form attributes, input types, and other helper elements, browsers haven’t visually improved forms much. This is one area where Bootstrap really shines, because aligning and styling labels and inputs, validating forms, and showing error messages, can be tricky without some help.

First, Bootstrap sets all textual input elements, like <input>, <textarea>, and <select>, to 100% width of the parent form element. It also gives you the ability to choose between inline forms, which will render multiple labels and input fields in the same line, by using the .form-inline class, or horizontal forms, which use grids to align each input in its own row, by using the .form-horizontal class. And if you need to place plain text next to a form label, instead of the input field, you can give it the .form-control-static class to make it match the visual look of the form.

Maybe the greatest feature that Bootstrap brings to forms is validation styles for error, warning, and success states. These can be applied using the .has-warning, .has-error, and .has-success classes, respectively. Combining this with icons that can be placed inside the input forms, we can get quick and effective form validation effects, even without using any error text message.

Images and Icons

Images in Bootstrap can be made responsive by simply giving them the .img-responsive class. This will apply max-width:100%;height:auto; and display:block; to the image in question, so that it scales to the parent element.

Besides making images responsive, we can easily add different effects. For example, rounded corners are applied with the .img-rounded class, and the image can be shaped to be a circle by using .img-circle, or to a thumbnail by using .img-thumbnail class.

Bootstrap comes bundled with over 260 glyphs in font format, from the Glyphicons Halflings set. Jan Kovařík, author and designer of Glyphicons, has made them available for Bootstrap for free and under the same license as Bootstrap, which is awesome. Font icons have many advantages over plain raster images, a big one being that they are scalable. They can also easily be customized using just CSS, so manipulating size or color, or even adding a drop a shadow, is a breeze.

Buttons, Button Groups, and Button Dropdowns

Buttons are one of the things every browser renders totally differently. If you want to have consistent design across all browsers, this is potentially a big problem. Luckily, Bootstrap has an elegant solution for buttonsalso. And besides making them consistent, it brings a lot of variations to play with. You can apply the .btnclass to <a> and <input> elements. You can group a series of buttons together into a single line using the .btn-group class on the parent <div>. With a little help from JavaScript, you can create radio- and checkbox- style behavior on buttons. Or you can turn your buttons into dropdown menus by placing it within a .btn-group, and providing the proper menu markup of unordered list of items.

Navbars

The navigational bar, or navbar, is a Bootstrap component designed specifically to build the primary navigation menu of the website. On big screens, it is displayed horizontally, and on small and mobile screens (those below 768px), it transformed into a “hamburger” dropdown menu. Under the hood, navbar is an unordered inline list of menu items, with additional HTML elements that are added as desired. Among the possible additions are branding (either text or logo), form items such as a search bar, and menu dropdowns. Two styles are available to choose from out-of-the-box: light and dark, inverted. Items in the navbar can be aligned left or right by applying .navbar-left or .navbar-right classes, respectively.

Navbars can have 4 different position behaviors. The default float position has buffer space around it; the full-width static navbar scrolls away when the user scrolls down the page, and the fixed navbar, which can be either on the top or the bottom of the window, is always visible on the page, no matter where the user has scrolled to.

Conclusion

This covers only a few of the great Bootstrap components that puts Bootstrap ahead of similar frameworks, libraries, and toolkits. With Bootstrap, just a few simple CSS classes are all it takes to build a fully responsive and beautiful front end, fast and easily. It’s a great starting point for your next big project or startup.

Full Original post @ https://www.toptal.com/front-end/what-is-bootstrap-a-short-tutorial-on-the-what-why-and-how